During a medical treatment, for example, surgery or stay in an intensive care unit, it is necessary to use various measuring instruments in the vicinity of the patient for monitoring physiological vital parameters (measured variables) of the patient, who is located, in general, on a patient care unit with a bed, for example, on an operating (OP) table.
The measuring instruments receive sensor signals, the sensors being used are, for example, sensors for measuring the oxygen saturation or the oxygen concentration, as well as sensors for measuring the CO2 concentration in the breathing air. Other sensor signals are generated by EKG electrodes. CCD (Charge Coupled Device) sensors are also used for image transmission to a monitor in minimally invasive surgery. The sensor signals are bound, in general, to lines, i.e., they are transmitted via electric lines to the particular measuring instruments, which are located, as a rule, outside the patient's direct area. The energy supply for the sensors is also provided mostly via electric lines, which are optionally integrated in a cable bundle.
A prior-art telemetry system for the transmission of EKG and sensor signals for the oxygen saturation of the blood has the drawback that a relatively high transmitting power must be selected in order to reliably make it possible to reach ranges of several meters. This may be associated with undesired physiological effects of electromagnetic fields on the body. In addition, the cable bundling and consequently the signal bundling of the individual sensors take place via a so-called “pod,” a cable connector, which lies loosely in a disturbing manner. In addition, a cable must be laid from the pod to the measuring instrument or to the monitor. In general, a plurality of measuring instruments and/or treating devices must be additionally networked with one another via lines, so that, on the whole, a plurality of electric cables hinder undisturbed access to the patient.